A United Nations human rights investigative team said that it has received permission from the Sudanese government to travel to Darfur in western Sudan, within days, to look into allegations of atrocities committed by government troops and militias allied to Khartoum. At the same time, the Sudanese government, citing security concerns, has delayed a U.N. humanitarian team's mission to Darfur by a week.

A Geneva-based spokesman for the United Nations Human Rights Commission, Jose Diaz, said a five-member team was in Chad for more than a week earlier this month.

The U.N. team interviewed hundreds of refugees who had escaped alleged ethnic cleansing by government-backed Arab militias in Darfur. Mr. Diaz said that team members asked for cooperation from the Sudanese government to investigate the allegations.

"The intention of the fact-finding team was to go interview both the refugees and also to go into Darfur and hold talks with Sudanese officials in Khartoum," he said. "We had asked for authorization to go into Darfur and we were waiting to have a response from the authorities, and the response came in only now."

The same five-member team is now preparing to leave Geneva. It is not yet clear when they will arrive in Darfur or how long the mission will be.

Mr. Diaz added that once the team is back in Geneva, it will submit a full report to the United Nations' high commissioner on human rights for further action.

The conflict in Darfur erupted more than a year ago after two rebel groups accused the Sudanese government of neglecting the impoverished region and took up arms. More than 10,000 people have died in the fighting, which has displaced a million people in the region. More than 100,000 others have fled to neighboring Chad.

Last week, the United Nations announced that a high-level delegation, led by the world body's top emergency relief coordinator, Jan Egeland, would be in Darfur this week to access the desperate humanitarian crisis there.

However on Tuesday, the United Nations said Khartoum has delayed the relief mission for a week because of what Sudanese officials described as security concerns.

U.N. officials privately said that they believe Khartoum is angry over remarks Mr. Egeland has recently made in public, accusing the government of carrying out a scorched earth policy against Africans in Darfur.

The United Nations said that the aid mission will go ahead next week without Mr. Egeland, who has other commitments and cannot make the trip.

Meanwhile, peace talks set to resume Tuesday between Darfur rebels and the Sudanese government in Chad have been delayed by a day. During the last round of talks earlier this month, the government and rebels agreed to a 45-day cease-fire that also called for the safe passage of humanitarian aid, the freeing of prisoners and the disarming and disbanding of Arab militias.